In a conventional technique, machine tools are known which relatively move tool with respect to workpieces so as to perform machining such as cutting. In addition, among such machine tools, there is known a machine tool of a numerical control type that designates a path of the tool on the basis of coordinates or the like of a prescribed feed axis and performs machining while moving the tool relative to the workpiece. By moving at least one of the workpiece and the tool according to a command from a control apparatus, the machine tool automatically performs machining while changing a relative position of the tool with respect to the workpiece.
In the machine tool of the numerical control type, a machining program in which the relative position of the tool with respect to the workpiece is set, and tool information or the like is inputted to the control apparatus in advance. The control apparatus for the machine tool performs machining of the workpiece on the basis of such information. An operator needs to set or confirm information on machining such as the machining program. Accordingly, a display part that displays the information on machining is arranged in the machine tool.
Japanese Unexamined Patent Publication No. 2-194403 discloses a numerical control apparatus for a machine tool, which has an operation mode such as a manual operation mode, an automatic operation mode, and a program mode. It is disclosed that the numerical control apparatus displays lists of an operation mode and an operation function of each operation mode in a tree structure, and the operation function of each operation mode can be confirmed or set.